FASHION OR PORN

I love fashion. I love clothes. I love editorials. But every once in a while I just don't get it. What is the purpose of showing a models boobs while only wearing a skirt? Will that make the consumer want to run out & buy that skirt b/c they hope their boobs will look the same? Or what about when a model is completely naked & only wearing shoes. I know some can argue & say that it's artistic but sometimes I just don't get it.  Enjoy.